000 00273nam a2200121Ia 4500
008 211209s1977 xx 000 0 und d
041 _aeng
082 _a515.33 N77 BOL
100 _aBOLTYANSKY V G
245 _aDIFFERENTIATION EXPLAINED
260 _c1977
300 _a64
999 _c15234
_d15234